Thermally assisted magnetic recording or heat assisted magnetic recording (HAMR) generally refers to the concept of locally heating a recording medium to reduce the corecivity of the medium. Such reduced coercivity allows the applied magnetic writing fields to more easily direct the magnetization within the recording medium during the temporary magnetic softening caused by the heat source.
In HAMR, information bits are recorded on a data storage medium at elevated temperatures, and the data bit dimension can be determined by the dimensions of the heated area in the storage medium or the dimensions of an area of the storage medium that is subjected to a magnetic field. In one approach, a beam of light is condensed to a small optical spot onto the storage medium to heat a portion of the medium and reduce the magnetic coercivity of the heated portion. In some implementations, a single switch controls power to the beam of light and also to a write coil of a write element.